each strain has its own SNP (single nucleotide polymorphism) mutations in which time frame?

Question

[2001linana]

Hi. I was reading an article and encountered this. "The SNP mutations including nucleotide changes and the corresponding positions in a genome are called an SNP profile." I assume this talks about the nucleotide changes (during mutations) and the corresponding positions in a genome. The question is, mutation is a time varying process. So, this SNP profile is in which time frame? Is it from the birth of the strain until death? Is this SNP profile the SNP mutations of this strain?

[swbarnes2]

An article about what? Bacterial populations? Tumors?

[2001linana]

The article is here: https://www.sciencedirect.com/science/article/pii/S0888754320303189